title: Evaluation of quantitative head impulse testing using search coils versus video-oculography in older individuals.
abstract: OBJECTIVE
  To evaluate the validity of 2D video-oculography (VOG) compared with scleral search coils for horizontal AVOR gain estimation in older individuals.
  
  
  METHODS
  Cross-sectional validation study.
  
  
  METHODS
  Tertiary care academic medical center.
  
  
  METHODS
  Six individuals age 70 and older.
  
  
  METHODS
  Simultaneous eye movement recording with scleral search coil (over right eye) and EyeSeeCam VOG camera (over left eye) during horizontal head impulses.
  
  
  METHODS
  Best estimate search coil and VOG horizontal AVOR gain, presence of compensatory saccades using both eye movement recording techniques.
  
  
  RESULTS
  We observed a significant correlation between search coil and VOG best estimate horizontal AVOR gain (r = 0.86, p = 0.0002). We evaluated individual head impulses and found that the shapes of the head movement and eye movement traces from the coil and VOG systems were similar. Specific features of eye movements seen in older individuals, including overt and covert corrective saccades and anticompensatory eye movements, were captured by both the search coil and VOG systems.
  
  
  CONCLUSIONS
  These data suggest that VOG is a reasonable proxy for search coil eye movement recording in older subjects to estimate VOR gain and the approximate timing of corrective eye movements. VOG offers advantages over the conventional search coil method; it is portable and easy to use, allowing for quantitative VOR estimation in diverse settings such as a routine office-based practice, at the bedside, and potentially in larger scale population analyses.
authors.affiliation: *Department of Otolaryngology-Head and Neck Surgery, and †Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland; ‡Neuroscience Research Australia and the University of New South Wales, Sydney, Australia; §German Center for Vertigo and Balance Disorders (IFB LMU), University Hospital Munich, Campus Grosshadern; and ∥Lausitz University of Applied Sciences, Senftenberg, Germany.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Agrawal
authors.forename: Michael C
authors.initials: MC
authors.lastname: Schubert
authors.forename: Americo A
authors.initials: AA
authors.lastname: Migliaccio
authors.forename: David S
authors.initials: DS
authors.lastname: Zee
authors.forename: Erich
authors.initials: E
authors.lastname: Schneider
authors.forename: Nadine
authors.initials: N
authors.lastname: Lehnen
authors.forename: John P
authors.initials: JP
authors.lastname: Carey
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D053483:Eye Movement Measurements / Q000295:instrumentation*; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D019416:Head Movements / Q000502:physiology*; D006801:Humans; D008297:Male; D014741:Video Recording